body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 2rem;
  background: #f5f5f5;
  color: #333;
}

header, footer {
  background: #222;
  color: #fff;
  padding: 1rem;
  text-align: center;
}

main {
  padding: 2rem;
  text-align: center;
}

button {
  padding: 0.5rem 1rem;
  font-size: 1rem;
  cursor: pointer;
}